motor

Abstract

DEPCT65 The motor is equipped with bushings that protect the hinge (part) from damage. Specifically, motor 1 consists of a stator 2 with a stator core 21 and windings 23, and a casing. Outside of the 6 motors with the same stator enclosure, the circuit board is mounted in the outer casing of the motor mentioned above. Bushing 7 secures the wires pulled from the circuit board above to the outside of the installed housing. In the outer casing of the motor above, the bushing above connects the first clamping piece 7A, the second clamping piece 7B, and so on. One end of the 7C of the first clamping piece above and the second clamping piece above are joined together and have a flared section. The 73mm folding open / close mechanism connects the other end (7AC and 7BC) of the first clamping piece above and the clamping piece. The two above are either close together or separated at the first clamping piece above and the second clamping piece. Each of the above pieces has a 74-degree angle control section that controls the opening angle of the hinge section above. -----------------------------------------------------------

Description

electric motor

[0001] The present invention relates to an electric motor provided with a bushing through which wiring of a control circuit board passes.

[0002] Among conventional electric motors, there is known an inner rotor type permanent magnet electric motor, in which a rotor having a permanent magnet is rotatably arranged inside a stator that generates a rotating magnetic field. This type of permanent magnet electric motor is used, for example, to drive the rotation of a blower fan installed in an air conditioner.

[0003] A known permanent magnet motor of this type has an internal control circuit board with wiring connected to the circuit board extending to the outside via a bushing. One such bushing is one that is divided into a pair of retaining pieces, a first retaining piece and a second retaining piece, and that are connected via a connecting portion (see, for example, Patent Document 1).

[0004] Dividing the bushing into two retaining pieces makes it easier to thread the wires through the bushing. Also, by connecting the two retaining pieces via a connecting part, the two retaining pieces do not come apart, improving assembly.

[0005] JP 2013-138551 A

[0006] In consideration of ease of assembly, hinges are generally used as the connecting portion. In this case, if the hinge opens excessively, the load applied to the hinge may cause the hinge to break, which may damage the bushing. It has been desired to prevent this damage.

[0007] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an electric motor equipped with a bushing that can prevent damage to the hinge (portion).

[0008] One aspect of the electric motor of the present invention includes a stator having a stator core and a winding, a motor housing that covers the stator, a circuit board disposed within the motor housing, and a bushing attached to the motor housing and holding wiring extending from the circuit board to the outside of the motor housing. The bushing has a first retaining piece, a second retaining piece, and a hinge portion. The hinge portion connects one end of the first retaining piece to one end of the second retaining piece, and opens and closes in a direction that moves the other end of the first retaining piece toward or away from the other end of the second retaining piece. Each of the first retaining piece and the second retaining piece is provided with an angle limiting portion that limits the opening angle of the hinge portion.

[0009] According to the present invention, damage to the hinge in the bushing of the electric motor can be prevented.

[0010] 6 is a perspective view of a rotor of a permanent magnet electric motor according to the present invention. FIG. 7 is a perspective view of a rotor, a shaft, and a second bearing of a permanent magnet electric motor according to the present invention. FIG. 8 is a perspective view showing a state after the rotor of FIG. 2 has been assembled to a motor shell. FIG. 9 is a cross-sectional view of a permanent magnet electric motor according to the present invention. FIG. 10 is an enlarged perspective view (a) and an enlarged plan view (b) showing an accommodation groove of a motor shell for accommodating a bushing according to the present invention. FIG. 11 is a front perspective view of a bushing according to an embodiment of the present invention in a closed state. FIG. 12 is a rear perspective view (a) and a front perspective view (b) of the bushing of FIG. 6 in an open state. FIG. 13 is a rear view (a) of a bushing according to an embodiment of the present invention in an open state, and a rear view (b) of a bushing according to a first embodiment of the present invention in an open state. FIG. 14 is a rear view (a) of a bushing according to an embodiment of the present invention in an open state, and a rear view (b) of a bushing according to a second embodiment of the present invention in an open state. FIG. 15 is a perspective view (a) showing a state before the bushing of FIG. 6 is attached to the motor shell of FIG. 3, and a perspective view (b) showing a state after attachment. 6A and 6B are enlarged perspective and plan views showing a state after the bushing of FIG. 6 has been accommodated in the accommodation groove of FIG. 5. FIG. 6B is a perspective view of a permanent magnet electric motor according to the present invention. FIG. 6B is a longitudinal sectional view of a permanent magnet electric motor according to the present invention.

[0011] Next, an embodiment of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and may differ from the actual product. Therefore, specific components should be determined by taking the following description into consideration.

[0012] Furthermore, the embodiments shown below are merely examples of devices and methods for embodying the technical concept of the present invention, and the technical concept of the present invention does not limit the shape, structure, arrangement, etc. of the components to those described below. The technical concept of the present invention can be modified in various ways within the technical scope defined by the claims.

[0013] An electric motor according to an embodiment of the present invention will be described below.

[0014] 1 to 13 are diagrams illustrating the configuration of an electric motor 1 according to this embodiment. As shown in these figures, the permanent magnet electric motor 1 is, for example, a brushless DC motor. Although not shown, the electric motor 1 is used to rotate a blower fan mounted in the outdoor unit of an air conditioner, for example.

[0015] The following description will be given taking as an example an inner rotor type permanent magnet motor 1 in which a rotor 3 having permanent magnets 31 is rotatably arranged inside a stator 2 that generates a rotating magnetic field. The permanent magnet motor 1 in this embodiment includes a stator 2, a rotor 3, and a motor housing 6.

[0016] 3, 4, and 13, the stator 2 includes a stator core 21 having a cylindrical yoke and a plurality of teeth extending radially inward from the yoke, and windings 23 wound around the teeth via insulators 22. The stator 2 is covered with a motor casing 6 made of resin, except for the inner peripheral surface of the stator core 21. In other words, the motor casing 6 covers the stator 2 (stator) including the stator core 21 and the windings 23. The motor casing 6 may be made of a metal such as steel plate or aluminum.

[0017] 5 and 10 , the motor casing 6 has a groove 64 formed at the end opposite the output side of the electric motor 1, into which a bushing 7 (described later) is attached. The shape of this groove 64 (and the second flange portion 712 of the bushing 7) may be any shape that allows the bushing 7 to be attached (held) to the motor casing 6. In this embodiment, the groove 64 is a nearly rectangular cutout that has a bottom on the output side in the direction of the central axis O of the motor casing 6 (hereinafter referred to as the central axis direction) and penetrates in the radial direction.

[0018] The groove 64 has a wall 641 against which a second flange 712 of the bushing 7 (described later) abuts, thereby restricting radial movement of the bushing 7. As shown in FIG. 5B , the groove 64 has a convex shape extending radially outward when viewed from the central axis direction. A waterproof wall 643 is provided at the bottom of the groove 64 of the motor outer casing 6, radially covering a cutout 714 of the second flange 712 (described later) to prevent water and dust from entering through the cutout 714. Similarly to the wall 641, the waterproof wall 643 also abuts against the second flange 712 of the bushing 7 (described later), restricting radial movement of the bushing 7. The groove 64 also has a bottomed hole 642 (recess) against which an angle restricting portion 74 of the second flange 712 (described later) is positioned. The hole 642 has a rectangular shape when viewed from the central axis direction.

[0019] The rotor 3 is rotatably disposed on the inner periphery of the stator core 21 of the stator 2 with a predetermined gap therebetween. As shown in Figures 2 and 13, the rotor 3 is a surface magnet type with permanent magnets 31 arranged annularly on the outer periphery facing the stator core 21. The permanent magnets 31 are fixed around a shaft 35 via an outer periphery core 32, an insulating member 33, and an inner periphery core 34. The shaft 35 is supported by a first bearing 41 and a second bearing 42, and the first bearing 41 is supported by a first bracket 51, and the second bearing 42 is supported by a second bracket 52, thereby rotatably supporting the rotor 3.

[0020] 13 , the first bearing 41 rotatably supports one end (output side) of the shaft 35 of the rotor 3. The second bearing 42 rotatably supports the other end (non-output side) of the shaft 35 of the rotor 3. The first bearing and the second bearing 42 may be ball bearings, for example.

[0021] The first bracket 51 is made of metal (such as steel plate or aluminum) and is disposed on one end of the motor casing 6 in the axial direction, i.e., on the output side of the shaft 35. The first bracket 51 is insert-molded when the motor casing 6 is molded, and is integrated with the motor casing 6. The second bracket 52 is made of metal (such as steel plate or aluminum) and, as shown in FIGS. 12 and 13 , is fixed to the other end of the motor casing 6 in the axial direction, i.e., on the side opposite the output side of the shaft 35. The second bracket 52 is formed in a generally circular disk shape and has an outer edge portion 520 that abuts the end surface of the motor casing 6 in the axial direction. The outer edge portion 520 is screwed to the outer edge of the motor casing 6. A second bearing receiving portion 522 for receiving the second bearing 42 is formed on the inner side (output side) of the center of the second bracket 52.

[0022] The second bracket 52 also has a heat dissipation fin 523 on its anti-output side that stands outward (anti-output side), and is in contact with a circuit board 82 for controlling the electric motor 1 via a heat transfer member 81. In other words, the second bracket 52 also functions as a heat sink that dissipates heat from the circuit board 82 (particularly, electronic components 821 mounted on the circuit board 82) to the outside of the electric motor 1.

[0023] <Insulation Structure of Rotor 3> In the permanent magnet motor 1 configured as above, as shown in Fig. 1, an insulating member 33 is provided in a portion of the rotor 3 to prevent electrolytic corrosion from occurring in the first bearing and the second bearing 42. The insulation structure of the rotor 3 will be briefly described below.

[0024] As shown in Figures 1 to 4, the rotor 3 includes, from the outer diameter side to the inner diameter side, a permanent magnet 31, an outer circumference side iron core 32, an insulating member (connecting portion) 33, an inner circumference side iron core 34, and a shaft 35.

[0025] 2 and 4, the permanent magnet 31 is formed in an annular shape by a plurality of (e.g., eight or ten) permanent magnet pieces 311 so that the north and south poles alternate at equal intervals in the circumferential direction. Note that the permanent magnet 31 may also be a plastic magnet formed in an annular shape by solidifying magnetic powder with resin.

[0026] 1 to 4, the outer core 32 is formed in an annular shape and is located on the inner diameter side of the permanent magnet 31. The outer core 32 is provided with a plurality of (e.g., 10 in the circumferential direction) outer projections 322 that project outward from the outer peripheral surface in order to position the permanent magnet 31. For example, the outer projections 322 are formed to extend from one end to the other end of the outer core 32 in the central axial direction.

[0027] As shown in FIGS. 1 to 4 , the inner core 34 is formed in an annular shape and is located radially inward of the outer core 32. The inner core 34 has a through-hole 343 at its center that penetrates in the axial direction. The shaft 35 is fixed to the through-hole 343 in the inner core 34 by press-fitting, caulking, or the like. The inner core 34 may have a plurality of through-holes 342 between the through-hole 343 and the outer surface of the inner core 34 for lightening purposes to reduce weight. These through-holes 342 are arranged at equal intervals in the circumferential direction so that the inner core 34 with the through-holes 342 formed therein has a spoke-like shape when viewed in the axial direction.

[0028] The insulating member 33 is formed from a dielectric resin such as PBT (polybutylene terephthalate) or PET (polyethylene terephthalate), and is located between the outer core 32 and the inner core 34. The insulating member 33 is molded integrally with the outer core 32 and the inner core 34 by insert molding, in which resin is filled between the outer core 32 and the inner core 34. The insulating member 33 reduces the electrostatic capacitance between the outer core 32 and the inner core 34 (part of the electrostatic capacitance between the winding 23 of the stator 2 and the shaft 35), and is adjusted to reduce the potential difference between the inner and outer rings by lowering the potential on the inner ring sides of the first bearing 41 and the second bearing 42, thereby preventing electrolytic corrosion of the bearings.

[0029] <Structure, Function, and Effects of Bushing According to the Present Invention> The electric motor 1 includes a bushing 7 for passing wires from the inside of the motor outer casing 6. In detail, as shown in Fig. 13 , the electric motor 1 includes the motor outer casing 6 and a circuit board 82 disposed within the motor outer casing 6. The circuit board 82 is disposed in a position between the rotor 3 and the second bearing 42 in the central axial direction. As shown in Fig. 10 , the bushing 7 is attached to the motor outer casing 6 and holds wires (not shown) that are drawn from the circuit board 82 (not shown) to the outside of the motor outer casing 6.

[0030] 6 to 8 are diagrams illustrating the structure of the bushing 7 in this embodiment. The bushing 7 includes an attachment portion 71 that is attached to the groove 64 of the motor housing 6 described above, and a wire-passing portion 72 through which the wires are passed. The wire-passing portion 72 is cylindrical, and the wires are passed through the interior thereof. The attachment portion 71 is rectangular parallelepiped-shaped, and is integrated with the wire-passing portion 72 so that the wires pass through in the X-axis direction in FIG. 6. The attachment portion 71 and the wire-passing portion 72 are not limited to the shapes described above.

[0031] The wire-passing portion 72 has a plurality of protrusions 721 on its cylindrical outer peripheral surface. This increases the strength of the wire-passing portion 72. In the present embodiment, as an example, four of the plurality of protrusions 721 are provided at equal intervals in the circumferential direction. The mounting portion 71 may be formed with a plurality of bottomed lightening grooves 713 along the cylindrical axis of the wire-passing portion 72. In the present embodiment, the lightening grooves 713 are four approximately triangular prism-shaped holes with one side curved in an arc shape, at positions that do not overlap with the protrusions 721 provided on the outer peripheral surface of the cylindrical wire-passing portion 72 in the X-axis direction.

[0032] As shown in Fig. 11 , a first flange 711 extending in the Y-axis direction is provided at an upper portion (positive Z-axis side in Fig. 6 ) of the outer surface side (positive X-axis side in Fig. 6 ) of the mounting portion 71. The first flange 711 cooperates with an upper end portion of the outer peripheral surface of the motor outer casing 6 to restrict radial movement of the bushing 7 and secure the bushing 7 to the motor outer casing 6 (see Figs. 6 to 11 ). As shown in Fig. 11 , a second flange 712 extending in the Y-axis and Z-axis (center axis O) directions is provided at a lower portion (negative Z-axis side in Fig. 6 ) of the inner surface side (negative X-axis side in Fig. 6 ) of the mounting portion 71. The second flange portion 712 cooperates with the wall portion 641 and the waterproof wall portion 643 provided in the groove portion 64 of the motor outer casing 6 to restrict radial movement of the bushing 7 and fix the bushing 7 to the motor outer casing 6 (see FIGS. 6 to 11 ). In this embodiment, the end of the first flange portion 711 on the negative Z-axis side and the end of the second flange portion 712 on the positive Z-axis side are at the same height (same position in the Z-axis direction) when viewed from the X-axis direction. Note that the first flange portion 711 and the second flange portion 712 are not limited to the above-described shapes as long as they can restrict movement of the bushing 7 relative to the motor outer casing 6.

[0033] 7, the bushing 7 is divided into a first retaining piece 7A and a second retaining piece 7B from the upper part (positive Z-axis side) of the bushing 7 at the center in the Y-axis direction (see FIG. 6), and the first retaining piece 7A and the second retaining piece 7B are integrally connected via a hinge portion 73 provided at the lower part (negative Z-axis side) of the bushing 7. Therefore, the above-mentioned first flange portion 711 and second flange portion 712 are formed on the first retaining piece 7A and the second retaining piece 7B, respectively (see FIG. 7).

[0034] The bushing 7 has a first retaining piece 7A, a second retaining piece 7B, and a hinge portion 73. The hinge portion 73 connects one end 7C of the first retaining piece 7A in the Z-axis direction (see FIG. 6 ) to one end 7C of the second retaining piece 7B in the Z-axis direction, and opens and closes in a direction that moves the other end 7AC of the first retaining piece 7A in the Z-axis direction toward or away from the other end 7BC of the second retaining piece 7B in the Z-axis direction. The hinge portion 73 is a thin (e.g., 0.5 mm) bendable living hinge integrally formed between the first retaining piece 7A and the second retaining piece 7B. In this embodiment, the hinge portion 73 is formed so that the width of the portion connecting the first retaining piece 7A and the second retaining piece 7B is narrow. In other words, the first end 7C of the first holding piece 7A and the second end 7C of the second holding piece 7B are connected by the hinge portion 73 while they are close to each other. This prevents the hinge portion 73 from protruding too far from the outer circumferential surface of the bushing 7 when the other end 7AC of the first holding piece 7A and the other end 7BC of the second holding piece 7B are brought close to each other. Therefore, when the bushing 7 is attached to the groove 64 as shown in FIG. 10 , it is not necessary to provide a large clearance in the groove 64 to avoid the hinge portion 73. Furthermore, this reduces the gap between the motor housing 6 and the bushing 7, preventing water and dust from leaking through the gap. On the other hand, if the width of the hinge portion 73 at the portion connecting the first holding piece 7A and the second holding piece 7B is short, the hinge portion 73 is less likely to deform. This increases the force required to open the bushing 7, resulting in increased stress on the hinge portion 73 when the bushing 7 is opened. That is, an excessive load is applied to the hinge portion 73 by the action of opening the bushing 7, which causes a problem that the hinge portion 73 is easily damaged. To solve this problem, in this embodiment, an angle restriction portion 74 is provided that restricts the angle at which the bushing 7 opens.

[0035] A first engagement portion 715A is formed near one end 7C of the first holding piece 7A, and a first engagement portion 715B is formed near one end 7C of the second holding piece 7B. The first engagement portion 715A of the first holding piece 7A and the first engagement portion 715B of the second holding piece 7B engage with each other when the bushing 7 is closed by the hinge portion 73. A second engagement portion 716A is formed at the other end 7AC of the first holding piece 7A, and a second engagement portion 716B is formed at the other end 7BC of the second holding piece 7B. The second engagement portion 716A of the first holding piece 7A and the second engagement portion 716B of the second holding piece 7B engage with each other when the hinge portion 73 is closed. Furthermore, when the bushing 7 is closed by the hinge portion 73, these engaging portions 715A, 715B, 716A, and 716B also function as a labyrinth structure that prevents water and dust from passing through these engaging portions in the X-axis direction of the bushing 7. The second engaging portions 716A and 716B are formed into a two-stage labyrinth structure with a semi-cylindrical and rectangular shape in the X-axis direction to enhance the sealing effect.

[0036] The second flange portion 712A of the first holding piece 7A and the second flange portion 712B of the second holding piece 7B have cutout portions 714A and 714B formed at one end 7C of the first holding piece 7A and one end 7C of the second holding piece 7B, respectively (see FIGS. 7 and 8 ). This allows the bushing 7 to open and close around the hinge portion 73. Furthermore, the cutout portions 714A and 714B form opposing cutout surfaces (first restriction surface 714C and second restriction surface 714D) on the first holding piece 7A and the second holding piece 7B, respectively. Furthermore, each of the first holding piece 7A and the second holding piece 7B is provided with an angle restriction portion (stopper) 74 that restricts the opening angle of the bushing 7. In other words, the angle restricting portion 74 is formed on each of the second flange portion 712A of the first holding piece 7A and the second flange portion 712B of the second holding piece 7B.

[0037] In this embodiment, as shown in Figures 7 and 8, the first holding piece 7A and the second holding piece 7B are each provided with the above-mentioned cutout surfaces (restriction surfaces 714C, 714D) as the angle restriction portion 74. For example, as shown in Figures 7(b) and 8(a), the angle restriction portion 74 (restriction surfaces 714C, 714D) is formed on the second flange portions 712A, 712B in locations close to the hinge portion 73. Then, as shown in Figure 8(a), for example, when the bushing 7 opens, the ends of the restriction surfaces 714C, 714D butt against each other, preventing the bushing 7 from opening any further. This restricts the opening angle of the bushing 7. Furthermore, the angle restricting portion 74 may restrict the opening angle not only by direct contact of portions of the restricting surfaces 714C, 714D provided on the first holding piece 7A and the second holding piece 7B, but also indirectly restrict the opening angle of the bushing 7 via a member located between the opposing cutout surfaces (restricting surfaces 714C, 714D). For example, as shown in FIG. 8( b), if the thickness t of the flange connecting portion 714E connecting the second flange portions 712A, 712B is large, when attempting to close the bushing 7, the presence of the thick flange connecting portion 714E between the opposing cutout surfaces (restricting surfaces 714C, 714D) indirectly prevents the opposing cutout surfaces (restricting surfaces 714C, 714D) from approaching each other, thereby restricting the opening angle of the bushing 7.

[0038] The angle restricting portion 74 (restriction surfaces 714C, 714D in FIG. 8( a ) and restriction surfaces 714C, 714D and flange connecting portion 714E in FIG. 8( b )) is provided at a position adjacent to the hinge portion 73 on one end 7C of the first holding piece 7A and one end 7C of the second holding piece 7B. In other words, the angle restricting portion 74 is provided on the side opposite to the side where the bushing 7 opens (the side of one end 7C). This makes it possible to restrict the opening angle of the bushing 7 using a simple mechanism (angle restricting portion 74). Furthermore, it is possible to prevent the angle restricting portion 74 from becoming large. By providing this second flange portion 712A and the angle restricting portion 74, it is possible to simultaneously restrict the radial movement of the bushing 7 relative to the electric motor 1 and the opening angle of the bushing 7.

[0039] In the present embodiment, the angle restricting portion 74 is formed at one end (second flange portion 712) of the bushing 7 in the X-axis direction (see FIG. 6 ), but is not limited to this and may extend partially (for example, from one end to the center of the bushing 7 in the X-axis direction) or entirely (from one end to the other end of the bushing 7 in the X-axis direction) as long as it functions as a stopper. Also, in the present embodiment, the angle restricting portion 74 is molded integrally with the bushing 7, but it may also be a separate part made of resin, elastic material, or the like that is adhered to the notched surfaces (restricting surfaces 714C, 714D) of the bushing 7.

[0040] As described above, when the bushing 7 is opened, the first holding piece 7A and the second holding piece 7B rotate about the hinge portion 73. At this time, the angle restriction portion 74 functions as a stopper that restricts the angle of rotation. This prevents the bushing 7 from being opened excessively, and damage to the hinge portion 73 can be prevented.

[0041] 9 is a rear view of a bushing 7' according to another embodiment. The bushing 7' is a cubic or rectangular parallelepiped member (mounting portion) 71', which has a through-hole 72' formed in the center for passing wiring. A second flange portion 712' extends in the Y-axis and Z(O)-axis directions from one side of the rear surface of the bushing 7'.

[0042] Similar to the bushing 7 in FIG. 7 , the bushing 7′ comprises a pair of first and second retaining pieces 7A and 7B, a pair of members (mounting portions) 71A′ and 71B′, and a pair of flange portions 711A′ and 711B′, which rotate about a hinge 73′ to open and close the bushing 7′. As shown in FIG. 9 , the pair of flange portions 711A′ and 711B′ have cutout portions 714A′ and 714B′ formed at the other ends 7AC and 7BC of the first and second retaining pieces. This allows the bushing 7′ to open and close about the hinge portion 73′. Furthermore, a pair of opposing cutout surfaces (a first restricting surface 714C and a second restricting surface 714D) are formed on the surfaces that approach each other when the bushing 7′ is opened.

[0043] In this embodiment, a pair of cutout surfaces (first restriction surface 714C and second restriction surface 714D) restrict the opening angle of hinge portion 73. That is, these first restriction surface 714C and second restriction surface 714D function as angle restriction portion 74.

[0044] When the bushing 7 is opened as shown in FIG. 9 , the first retaining piece 7A' and the second retaining piece 7B' rotate around the hinge portion 73'. At this time, the first restricting surface 714C and the second restricting surface 714D come into surface contact and function as an angle restricting portion (stopper) to prevent the bushing 7' from opening more than necessary. This prevents the bushing 7' from opening excessively and prevents damage to the hinge portion 73'. In this case, the angle formed by the first restricting surface 714C and the second restricting surface 714D when the bushing 7' is closed (see FIG. 9( a) ) becomes the opening angle (the angle formed by the dividing surfaces 7D of the first retaining piece 7A' and the second retaining piece 7B') that is restricted when the bushing 7' is fully open (see FIG. 9( b) ).

[0045] In Figure 9(b), the angle formed by the respective dividing surfaces 7D of the first retaining piece 7A' and the second retaining piece 7B' when the bushing 7' is fully open (the angle formed by the first regulating surface 714C and the second regulating surface 714D when the bushing 7' is closed as shown in Figure 9(a)) is 105.6 degrees, but this is not limited to this and it may be within a predetermined range (for example, 45 degrees or more and 135 degrees or less) that can prevent damage to the hinge portion 73'.

[0046] The bushings 7, 7' described above are components in which the first retaining pieces 7A, 7A' and the second retaining pieces 7B, 7B' are integrally molded, and are formed, for example, by resin injection molding. When the bushings 7, 7' described above are formed by resin injection molding, the opening angle of the bushings 7, 7' in the normal state when no external force is applied can be easily determined by adjusting the opening angle of the bushings 7, 7' at the time of manufacturing.

[0047] For example, it is preferable to mold the bushings 7, 7' so that they are slightly open when they are injection molded (for example, the angle formed by the dividing surfaces 7D of the first holding piece 7A' and the second holding piece 7B' in FIG. 9(b) is between 35 degrees and 125 degrees). This allows the bushings 7, 7' to be slightly open even in a normal state where no external force is applied, eliminating the need to open the bushings 7, 7' when passing wires through the wire-passing portion 72, improving workability.

[0048] After the wires are passed through the wire-passing portions 72, the second flange portions 712 of the bushing 7 (7') are inserted into the groove portions 64 of the motor casing 6 in the central axis direction, and the bushing 7 (7') is fixed to the motor casing 6 (see FIGS. 10 and 11). At this time, the first holding pieces 7A and second holding pieces 7B of the bushing 7 are arranged so that the dividing surface 7D (see FIG. 9(a)) is parallel to the central axis direction of the motor casing 6, and the outer surface of the bushing 7 is held by the side walls of the groove portions 64. This prevents the bushing 7 from cracking open at the dividing surface 7D during or after installation on the motor casing 6.

[0049] The bushing 7 is attached so that the hinge portion 73 is oriented in the direction (the output side of the electric motor 1) that it will fit into the motor housing 6. This prevents the bushing 7 from opening from the dividing surface 7D when fitting the bushing 7 into the motor housing 6.

[0050] As described above, in this embodiment, the angle regulating portion 74 (regulating surfaces 714C, 714D, flange connection portion 714E) is provided on the bushings 7, 7' as a stopper (angle regulating portion), and by regulating the opening angle of the bushing 7 attached to the motor outer casing 6, the load on the hinge portion 73 can be reduced and damage to the bushing 7 can be prevented.

[0051] DESCRIPTION OF SYMBOLS 1...Permanent magnet motor 2...Stator 21...Stator core 22...Insulator 23...Winding 3...Rotor 31...Permanent magnet 311...Permanent magnet piece 32...Outer circumferential core 33...Insulating member 34...Inner circumferential core 343...Through hole 35...Shaft 42...Second bearing 52...Second bracket 6...Motor outer casing (housing) 64...Groove portion 641...Wall portion 642...Hole portion 643...Waterproof wall portion 7...Bushing 71...Mounting portion 711, 712...Flange portion 714A, 714B...Notch portion 714C, 714D...Notch surface (regulating surface) 714E...Flange connecting portion 72...Wiring passage portion 7A, 7B...First holding piece, second holding piece 73...Hinge portion 74...Angle regulating portion (stopper) 81...heat transfer member 82...circuit board 821...electronic component O...center axis

Claims

DEPCT651. A motor which is assembled with a stator containing a stator core and windings, an outer casing for the stator, and a circuit board housed in the outer casing, and bushings mounted on the outer casing and holding the wires drawn from the circuit board to the outside of the outer casing. Such bushings have a first clamp, a second clamp, and a hinge. Such hinge connects one end of the first clamp to one end of the second clamp and opens and closes in a direction that brings the other end of the first clamp and the other end of the second clamp closer together or further apart. At each of the first and second clamps, there shall be an angle control which controls the opening angle of such hinge.

2. The motor specified in claim 1 in which such angle control is provided in a position adjacent to the hinge of one such end of the first clamp and one such end of the second clamp.3.

4. Any motor specified in Reservations 1-2, in which the first and second clamping pieces are formed a pair of flange sections that control the movement of such bushing in the radial direction of such motor housing, and such angle control sections are formed on such flange sections.

5. Any motor specified in Reservations 1-4, in which the motor housing has groove sections that are provided at the ends of such motor housing in the center-axial direction, the dividing surfaces of the first and second clamping pieces are laid parallel to such center-axial direction of such motor housing, and the outer surface of such bushing is clamped to the side walls of such groove sections. 6.The motor specified in claim 5, on which the said bushing is mounted, is positioned on the lower surface of the said groove provided on the motor's outer housing.